In regards to that, I would like to propose a suggestion: what i would/could do is post each month as its own thread to the forum first (and then in-game) and just edit the thread later to add in the other weeklies for that month below it since we can edit changes many times on the forum but not so much with the in-game fleet message cooldown. Then we can have the fleet message also reference back to the forum for a copy of the latest news if we delete it from the inbox and later find a need to reference it again...
Honestly I don't have the time, which is usually why I don't update that post. I spend a few minutes sending the message then I need to get off. I do need to make more of an effort of keeping it up to date, because I know some people accidentally delete the message for that week.
Frankly I don't see much purpose in having an archive of all the weekly messages, which is why I've never done it. They don't contain lasting information that we'll need to reference later on. Its info for that week only, anything that needs attention beyond that week is included in the following weeks' messages. I can't recall any instance that we needed to check an earlier week.
Even the promotions are not a big deal. You know if you got a promotion because you know how many commendations you've earned and can see if your fleet rank changed.